What is happening in week 13
Doctors count pregnancy weeks from the first day of your last period, so week 13 sits in the first trimester (up to the end of week 13). That is about 27 weeks to go until week 40, and about 3.0 months by a rough conversion. In week 13 the baby is about 7.4cm long and may begin sucking its thumb.
Your baby
The NHS guide gives about 7.4cm, comparing it to a peach. Movements are jerky at first and become more deliberate, and some babies suck their thumb, which builds the sucking reflex needed for feeding. You may not feel movement until around week 17, according to the NHS.
Your body
A small bump may show now as the womb grows upwards and outwards, and the need to pee often usually eases as the womb moves off the bladder. You may feel thirstier. Swollen or bleeding gums, round ligament pains and headaches are possible.
This week’s to-do
- Brush twice a day with a soft toothbrush and limit sugary snacks to protect your gums.
- Start gentle pelvic floor exercises.
- Take care with food hygiene: avoid undercooked meat and unpasteurised dairy, as the NHS advises.
When to call
Call your doctor or hospital if you have any bleeding, or if you may have been near someone with chickenpox or rubella.
Chaitanya Hospital in Kadapa, near RTC Bus Stand, Simhapuri Colony, provides delivery and emergency care 24/7. Our antenatal check-ups team can answer questions about your own pregnancy.
Use the week-by-week guide to jump to your week, or the due date calculator to work out your dates. Timings for scans and tests come from NHS guidance in the UK and can differ from your doctor’s schedule, so always follow your own doctor’s advice. This page is educational and not a substitute for a doctor.
Sources
Text on this page is paraphrased from the sources above. Sizes are averages and vary between babies.